Controversial Health Topic: Is Electricity Making Us Sick and Fat?

Electricity allows us to stay glued to our laptops or Xboxes until the wee hours of the morning, but it may have serious implications for our health and waistlines, according to a U.K. study published last year in the journal Bioessays.

“For thousands of years, we were up at sunrise and did most of our activities during daylight hours. When it was dark, we had little to do besides sleep,” explains study author Cathy Wyse, PhD, a research fellow in the school of biological sciences at the University of Aberdeen in Scotland. “But over the past century, we’ve come to rely on electricity and begun staying up late. This forces us to go against our natural circadian rhythms, which throws off important hormones like melatonin, insulin, and cortisol.” Other experts note that there’s strong evidence that shift workers have higher rates of breast cancer, heart disease, and diabetes.

Wyse first suspected there was a link between electricity and health back in 2005, as she was studying the effects of jet lag on the performance of racehorses. But her aha moment occurred a few years later, when she found that altering the usual amount of time that mice were exposed to darkness and light caused them to gain weight and shortened their life spans. “I remember thinking I’d made a mistake because the results were so consistent,” she recalls. “But when I repeated the study in other animals, I got the same results.” An earlier study seems to support Wyse’s theory. It showed that people who move north, away from the equator—where periods of daylight and nighttime remain constant throughout the year—to latitudes with greater night-day fluctuations experience more weight gain.